1. Field of the Invention
The present invention relates to a wireless communication system. More particularly, the present invention relates to an apparatus and a method for providing an efficient digital interface in cooperating with a baseband modem in a wireless communication system.
2. Description of the Related Art
The conventional wireless terminal was a receiver structure configured with one I/Q channel set, but the next generation terminal system has evolved into a Multi Input Multi Output (MIMO) structure that considers diversity and requires a plurality of I/Q channel sets. In other words, the next generation terminal system transmits/receives data via a plurality of Radio Frequency (RF) chains.
According to the related art, a 16-bit high resolution Analog-to-Digital Converter (ADC) output requires 32 bits (16×2=32 bits) based on one I/Q channel. For example, a Radio Frequency Integrated Circuit (RFIC) including the ADC requires 32 I/O pins or a modem chip requires 32 I/O pins. Meanwhile, the next generation wireless terminal system requires a 128-bit interface (e.g., 128 input/output pins) at the minimum. For example, because the next generation terminal system having an MIMO structure that considers diversity requires 4 I/Q channel sets, and 128 (=16×2×4) I/O pins are required.
As described above, in a 4th Generation (4G) mobile communication system, as a high resolution of an ADC and a wideband requirement are raised and an MIMO structure is introduced, a situation where an interface with an external modem becomes a burden occurs. In other words, the number of I/O pins of an RFIC including an ADC increases.
Generally, the number of I/O pins of an RFIC is designed as 100 pins in total, but 128 bits are required for only an output of a reception terminal and so chipset design becomes very difficult, and the chipset should be designed as a plurality of RFIC chips separately even though a technology for realizing the chipset in a single-chip exists. Because the plurality of RFICs are used, manufacturing costs may increase.
Also, a unit price of a substrate increases due to an area occupied by 128 I/O pins, signal quality deteriorates due to interference between digital signals, and power consumption for an interface increases.
Therefore, an apparatus and a method for providing an efficient interface for reducing the number of I/O pins between an RFIC and a modem are required.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.